11.3. Executing Perl Commands inside the Debugger

One can execute perl commands inside the debugger. For example, typing
print $x at the debugger prompt will print the value of the
$x variable. You can also modify the values of variables in this
way, or run functions, etc.

One special command that is also useful is x. x $var
displays $var in a hierarchical manner, which is very useful for
lists of lists etc. The Data::Dumper module which is available from
CPAN offers a similar functionality, from
within your perl programs.